Start practicing looking dangerous while you sleep.
You carry it around everywhere, and it can never be physically taken from you.
Obligatory xkcd refutal.
The first thing that popped into my mind was the short story by Isaac Asimov: Alexander the God.
If you rotate the screen 90 degrees and squint your eyes, you will see that it spells: Cthulhu Fhtagn
Kerckhoffs's Principle states:
A cryptosystem should be secure even if everything about the system, except the key, is public knowledge.
I thought this was just common sense.
While Scratch is geared towards 6 - 16 year olds, it may be worth a look.
Carlos Cotta and Álvaro Morales from the University of Malaga in Spain...suggest that using spacecraft that travel at a tenth of the speed of light, the colonization wavefront could take some 50 million years to sweep the galaxy.
"Any sufficiently advanced technology is indistinguishable from magic."
- Arthur C. Clarke
"Don't talk to me about disclaimers! I invented disclaimers!" -- The Censored Hacker